There has been known a chemical-mechanical polishing (CMP) apparatus for polishing substrate surfaces in the manufacture of semiconductor devices. In the CMP apparatus, a polishing pad is attached to the upper surface of a polishing table to form a polishing surface. In this CMP apparatus, the surface to be polished of a substrate held by a top ring is pressed against the polishing surface and the polishing table and the top ring are rotated while supplying slurry serving as a polishing liquid to the polishing surface. Consequently, the polishing surface and the surface to be polished are relatively moved in a sliding manner and the surface to be polished is thus polished. When polishing is performed in this way, abrasive grains and polishing sludge adhere to the polishing surface, and therefore, polishing characteristics degrade gradually according to the operating time of the polishing apparatus. For this reason, the polishing surface is dressed at a predetermined point of time using a dresser.